This invention relates generally to improvements in analog timepiece movements, and more particularly to movements for quartz analog timepieces intended to be powered by a large diameter thin energy cell and intended to operate with an electroluminescent lighted dial.
An analog timepiece movement of the general type is shown in U.S. Pat. No. 5,210,722 dated May 11, 1993 in the name of the present inventor and assigned to the present assignee. The movement illustrated in the aforementioned patent is of the type having a molded frame of insulating material with a peripheral side wall and a central wall rotatably supporting a dial side gear train on one side and a movement side gear train on the other side with the assistance of a bridge. The bridge and the central wall house the stepping motor and the movement side gear train which is connected, by means of a third wheel assembly to drive the dial side gear train which, in turn, drives the hour and minute hands of the timepiece. U.S. Pat. No. 5,210,722, which is incorporated herein by reference, is arranged on the movement side to contain a large diameter, thin energy cell. The printed circuit board with some discrete electronic components attached thereto is located in the frame beneath the energy cell, the latter being displaced to one side in an elliptical frame envelope to accommodate the quartz crystal adjacent the energy cell.
Analog wristwatches have recently begun to use electroluminescent lighting to illuminate the watch dials. An example of an electroluminescent watch dial is shown in U.S. Pat. No. 4,775,964 issued Oct. 4, 1988 in the names of Alessio et al, and assigned to the present assignee. Such an electroluminescent dial requires an efficient circuit to drive it, such a circuit being exemplified in U.S. Pat. No. 4,527,096 issued Jul. 2, 1985 to Kindlmann, incorporated in an integrated circuit, and also requires discrete electronic components such as one or more external inductors, which are usually carried on a separate printed circuit board (PCB) with the integrated circuit for the electroluminescent (EL) watch dial. Therefore the need to adapt the analog watch movement to function with an EL dial has necessitated a separate PCB and need to locate it along with its discrete components, as well as to make all of the additional required connections.
Each additional movement part, assembly and subassembly which must be handled adds to the cost of the analog timepiece. Therefore it is desirable to utilize a minimum number of components and to require each component to perform more than one function if possible. The electronic PCB assemblies should be completed to the greatest extent possible before assembly into the movement, at which time the number of connections made should be as few as possible. Also, the movement should be adaptable and flexible for use in many styles and models of watches.
Accordingly, one object of the present invention is to provide an improved analog timepiece movement for use with a large diameter energy cell and an electroluminescent dial.
Another object of the invention is to provide an improved quartz analog timepiece movement, provide an improved arrangement for the frame and printed circuit board with discrete electronic components.
Still another object of the invention is to provide an improved quartz analog timepiece movement utilizing a minimum number of parts and requiring a minimum number of connections during assembly.